I tried to edit it to make a line by line comparison, but the code have no comments and it's getting hard for me to understand the logic (of how it works). May the original coder could give me some suggestions.

What I mean by line by line?
Currently it is displaying the result as a single column of a table, well, i want it in two columns.
Here is the original source code.

Thank you very much arnab for your tip. I took a look at google's API and it's very powerful, however I discarded it because I wanted face to face line diff. But after seeing your demo I realized that I can display the original one in one side and the result in the other. I'll take a look to your library.
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Danielo515Feb 10 '13 at 11:27